Drying kiln and process



M. L. MUELLER.

, DRYING KILN AND PROCESS.

APPLICATION FILED JULY 20,192]. 1 423336 Patented July 18, 1922,

2 SHEETSSHEET I.

M. L. MUELLER.

DRYING KILN AND PROCESS. APPLICATION FILED JULY 20,1921.

Patented July 18,1922.

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2 SHEETSSHEET 2.

z 0 w m i w V g lil. Z. lllllllllflllulllllllllfilllllil IIIJIIIIIIII. ll-Jillllll'l .I a u n u n m IT J E. J I J. E l I l I ll| |||l|||.-ll|ll|| MORITZ 1.. MUELLER, or SEATTLE, WASHINGTON, essreivon To NORTHWEST BLOWER KILN 00., on SEATTLE, WAsnINeToN, A CORPORATION OF WASHINGTON.

DRYING KILN AND PROCESS.

Application filed July 20,

To all whom it may concern Be it known that I, Monrrz L. M E LER, a citizen of the United States of America, and resident of the city of Seattle, in the county of King and State of vVVashington, have invented certain new and useful Improvements in Drying Kilns and Processes, of which the following is a specification.

My invention relates to a system of operating dry kilns and. also to the apparatus employed for carrying out this system.

i The object of my invention is to provide a simple and economically operated apparatus for kiln drying of products, particularly lumber, and the apparatus for carrying out the same in which a steam -driven motor is used for producing a positive circulation of the drying air and the exhaust steam from said motor is discharged into the circulation system.

The features of my invention which I believe to be new and upon which I desire to obtain a patent will be hereinafter described and. then particularly pointed out in the claims which terminate this specification.

In the accompanying drawings I have shown an apparatus which is in the form now preferred by me for carrying out my improved system.

Figure l is a plan view partially in section, showing a portion of a dry kiln and the apparatus for heating the circulating air and producing a positive circulation thereof through the kiln.

Figure 2 is a side elevation and partial section of the same apparatus.

The use of steam injected into a lumber dry kiln has heretofore been practiced. This, so far as known by me, has chiefly been confined to the injection of live steam directly to the kiln. In following out this process the amount of steam required amounts t a great many horse power and this is expensive to generate and also requires the provision of sufficient capacity in boilers, the use of fuel for producing the steam. and the cost of labor in tending boilers. By my present system of operation I employ a fan for producing a positive circulation and connect this up directly with a steam driven motor, preferably a turbine, and supply the steam which is desirable in the kiln drying of lumber, at least at cer Specification of Letters Patent.

Patented July 1 5%, i922.

1921. Serial No. recess.

tain stages thereof, by discharging the exhaust from this motor directly into the circulation. In this manner I am using no steam except such as has been previouslv employed for the generation of power. and therefore, the cost of the steam as employed in the dry kiln is nothing or at least negligible. I

In the drawing 9 represents a kiln which may be of substantially any standard construction. This kiln is supposed to be of a type in which a circulation of air is employed for drying the lumber. For this purpose I have shown the pipe l which is provided with openings 10 for the supply of air to the kiln and pipes 2'into which air is drawn from the kiln chamber and conveyed to the fan. This air as drawn from the kiln is first passed into and through the heater 3 and thence to the fan chamber 4.

Within the fan chamber is mounted a fan 5 which, in the form shown, is directly connected with a steam turbine 6. This turbine is supplied with steam through a pipe 60 from any convenient source. This turbine has an exhaust pipe 61 which has a branch connecting directly with the fan chamber at and controlled by the valve 62 and another branch controlled by a valve 63 which may be employed to conduct the exhaust for discharge outside of the kiln when this is desired.

iVhile I prefer to employ a steam turbine as the motor for driving the fan, any other form of steam driven motor would be a substantial equivalent. beneficial effect upon the lumber after it has been passed through the motor as it would have if discharged at high pressure directfrom the boiler. It is the moist heat of the steam which is desired in kiln drying. This moist heat is not desired at all times during the drying process. lVhen not desired the valve'62 is closed and the valve 63 opened, thus discharging the steam elsewhere than in the kiln. It will be observed that the exhaust steam from the engine is turned into the conduit adjacent the fan rather than into the main body of the kiln. The action of the fan thoroughly commingles the steam and air from the heater with the result that the air delivered to the body of the kiln and coming in contact with the lumber is The steam has as much rendered uniform throughout as regards its moisture content. The above apparatus employs standard elements which may be obtained cheaply and is in every respect simple in construction and reliable in its operation. Its cost is also much below that of other systems.

\Vliat I claim as my invention is:

1. In combination, a kiln, a fan for circulating air through said kiln, a steam driven engine for operating said fan and means for delivering the exhauststeam from said engine to the current of air circulated by said fan and in advance of said fan.

2. In combination, a kiln, conduits for delivering air to said kiln and withdrawing air therefrom, a fan for circulating air through said conduits, a steam engine for driving said fan, and means for delivering the exhaust steam from said engine to said conduits to be commingled with the air passing therethrough before the air enters the kiln.

3. In combination, a kiln, a fan casing, air circulating conduits of which said casing constitutes a part, a steam engine for operating the fan and means for delivering the exhaust steam from said engine to said casing.

i. In combination, a kiln, a heater, a conduit for delivering air from the heater to the kiln, a conduit for withdrawing air from the kiln and delivering it to the heater, a fan disposed in the conduit which leads from the heater to the kiln, a steam engine for driving said fan and means for delivering exhaust steam from said engine to the last named conduit in advance of said fan.

5. In combination, a kiln, a heater, a conduit leading from the kiln to the heater for withdrawing air from the kiln and delivering it to the heater, a conduit leading from the heater to the kiln for delivering air from the heater to the kiln, a fan disposed in the last named conduit and having its shaft axially aligned with said conduit, a turbine steam engine axially aligned with said conduit and directly connected to said fan and means for discharging the exhaust steam from said engine radially into said conduit in advance of said fan.

Signed at Seattle, King County, IVashington, this th day of July, 1921.

MORITZ L. MUELLER. 

